目的 揭示不同粒径分布的煤粉颗粒在法向载荷下的力链构型演化对其结合面接触特性的影响机制,建立含颗粒介质结合面接触刚度计算方法。方法 首先对接触表面的微观形貌进行了提取,然后通过相关实验对颗粒-颗粒间和颗粒-接触面间的相关接触参数进行标定,并基于改进的JKR接触理论与Tavares UFRJ破碎模型,通过FEM-DEM耦合方法建立了三体接触模型,然后分析了不同粒径分布下煤粉层的力学特性、接触表面的应力分布状态和接触刚度的变化,最后采用实验进行了验证。结果 小颗粒体系在不同载荷下的破碎效应都相对平缓,能形成均匀的密集力链网络来分散载荷的传递,使接触表面的应力分布均匀。而大颗粒体系能够形成方向性强的集中性力链,且随着载荷增大其破碎效应愈发显著,破碎后的小颗粒会逐渐填充间隙诱发力链网络的调整,逐渐形成以强力链主导、弱力链弥散分布的承载结构,使接触表面产生多处高应力区,在载荷加载稳定后的接触刚度会超过小颗粒体系,20~40 μm和20~100 μm分布模型在载荷0.05 MPa时的接触刚度分别3.536×108、3.956×108 Pa/m。结论 本研究明确了煤粉颗粒的初始粒径分布和破碎效应会共同影响其力链网络构型,进而导致结合面的接触刚度变化。建立了有效的含颗粒介质结合面接触刚度计算方法,为探究含颗粒介质界面的接触演化规律与动力学行为提供了理论依据。
Abstract
In this study, the effects of wet coal seams with different particle size distributions on the contact stiffness of joint surfaces are systematically explored through comprehensive experiments and numerical methods. Firstly, the contact parameters between particles and particles and between particles and contact surfaces are determined by stacking angle and inclined plate slip experiments under controlled humidity. Then, the crushing parameters of a Tavares UFRJ crushing model are calibrated by comparing the simulated and experimental stress-displacement responses through confined compression experiments. Based on these calibration parameters, a three-body contact model is established by the finite element-discrete element coupling method. The upper plate is a rigid body model subject to normal pressure. The wet pulverized coal layer is simulated by the discrete element method and periodic boundary conditions are applied. For the lower plate, the finite element method is applied to establish and fix the bottom boundary. At the same time, a special data mapping algorithm is developed to transfer the particle contact force to the finite element nodes. The simulation results fully reveal the mechanical behavior of the particle system. The analysis of the evolution of fragmentation rate and coordination number shows that under the load of 0.03 MPa, the fragmentation rate of the wide particle size distribution jumps nonlinearly from 8% to 14% in 3.3-3.6 ms, and the coordination number decreases sharply, indicating the occurrence of chain fragmentation and network collapse. The medium particle size distribution maintains a stable coordination number, which can effectively transfer stress and avoid large-scale crushing. Under the load of 0.05 MPa, the initial crushing of all distribution models increases rapidly, among which the crushing rate of 20-80 μm model is the highest, while the growth rate of 20-100 μm model is the slowest due to the buffering effect of fine particles. From the evolution process of pulverized coal particle breakage, it can be seen that there is a significant stress concentration effect in the asperity area due to the small contact area, which leads to the preferential breakage of the large particles in the area. The sub-particles produced by crushing gradually penetrate into the concave area on the surface of the guide rail, and fill the gap with small particles to form a covering layer effect, so as to optimize the force chain network structure of the pulverized coal layer, enhance its continuity and directivity, and improve the compactness and local stress dispersion ability of the contact interface. Then, the rose diagram and force chain visualization of the pulverized coal layer particles further show that the fine particle system forms a dense and isotropic force chain network, which promotes the uniform distribution of stress on the contact surface. The wide particle size distribution is significantly broken under the condition of high pre-tightening force dominated by large particles, which is reorganized into a dual-mode force chain structure, resulting in multiple high stress areas on the contact surface. Finally, the normal stiffness change of the pulverized coal layer and the stress distribution mode of the contact surface are systematically evaluated, and then the overall three-body contact stiffness is calculated. The quantitative results show that the contact stiffness of 20-40 μm and 20-100 μm models reaches 3.536×108 Pa/m and 3.956×108 Pa/m, respectively, under the compressive load of 0.05 MPa. Finally, the numerical prediction results are verified by the hammer excitation and the pulse excitation test carried out by the acceleration sensor, which shows that the experimental and simulated three-body contact stiffness values are highly consistent. This study provides new insights into the micromechanical behavior of granular media in humid environments and establishes a reliable modeling framework for analyzing contact characteristics in engineering applications involving particle-filled interfaces.
关键词
潮湿煤粉 /
颗粒破碎 /
力链结构 /
承载特性 /
微观形貌 /
三体接触刚度
Key words
wet pulverized coal /
crushing of particles /
force chain structure /
load bearing characteristics /
microscopic morphology /
three-body contact stiffness
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参考文献
[1] GODET M.The Third-Body Approach: A Mechanical View of Wear[J]. Wear, 1984, 100(1/2/3): 437-452.
[2] GODET M.Third-Bodies in Tribology[J]. Wear, 1990, 136(1): 29-45.
[3] WANG J N, YANG L, LI F, et al.Force Chains in Top Coal Caving Mining[J]. International Journal of Rock Mechanics and Mining Sciences, 2020, 127: 104218.
[4] GUPTA A, RAMESH K T, HURLEY R C.Instabilities in a Two-Dimensional Granular Fault Gouge: Particle Dynamics and Stress Fluctuations[J]. Journal of the Mechanics and Physics of Solids, 2024, 193: 105843.
[5] ZHANG Y Y, MOLLON G, DESCARTES S.Significance of Third Body Rheology in Friction at a Dry Sliding Interface Observed by a Multibody Meshfree Model: Influence of Cohesion between Particles[J]. Tribology International, 2020, 145: 106188.
[6] MENG F J, LIU K, TANG Z Q, et al.Multiscale Mechanical Research in a Dense Granular System between Sheared Parallel Plates[J]. Physica Scripta, 2014, 89(10): 105702.
[7] MENG F J, LIU H B, HUA S Z, et al.Force Chain Characteristics of Dense Particles Sheared between Parallel- Plate Friction System[J]. Results in Physics, 2021, 25: 104328.
[8] MENG F J, LIU H B, HUA S Z, et al.Experimental Research on Sliding Friction of Dense Dry Particles Lubricated between Parallel Plates[J]. Tribology Letters, 2021, 69(2): 33.
[9] AUDRY N, HARTHONG B, IMBAULT D.The Mesoscale Mechanics of Compacted Ductile Powders under Shear and Tensile Loads[J]. Journal of the Mechanics and Physics of Solids, 2024, 192: 105807.
[10] ZHANG W, ZHOU J, ZHANG X J, et al.Quantitative Investigation into the Relation between Force Chains and Stress Transmission during High-Velocity Compaction of Powder[J]. Journal of the Korean Physical Society, 2019, 74(7): 660-673.
[11] ZHANG W, YUAN C N, ZHANG S, et al.Correlation Mechanism of Friction Behavior and Topological Properties of the Contact Network during Powder Compaction[J]. Particuology, 2023, 82: 98-110.
[12] ZHANG W, XIAO W J, YUAN C N, et al.3D DEM Investigation on Percolation of Lubricant Particles during Uniaxial Metal Powder Compaction[J]. Granular Matter, 2024, 26(3): 56.
[13] 杨辛未, 孙东, 张帅, 等. 煤粉界面厚度影响下结合面接触刚度分析[J]. 振动与冲击, 2025, 44(2): 120-130.
YANG X W, SUN D, ZHANG S, et al.Contact Stiffness Analysis under the Influence of Pulverized Coal Interface Thickness[J]. Journal of Vibration and Shock, 2025, 44(2): 120-130.
[14] 周剑, 徐宏坤, 刘焜. 基于微观孔隙演变的Ti-6Al-4V粉末高速压制致密化机理研究[J]. 机械工程学报, 2024, 60(16): 180-189.
ZHOU J, XU H K, LIU K.Study on the Densification Mechanism of Ti-6Al-4V Powder during High Velocity Compaction Based on the Evolution of Microscale Pores[J]. Journal of Mechanical Engineering, 2024, 60(16): 180-189.
[15] YANG X W, WU D X, BAI Y X, et al.Identification of Force Chains in Wet Coal Dust Layer and the Effect of Porosity on Three-Body Contact Stiffness[J]. Scientific Reports, 2024, 14: 16822.
[16] YANG X W, WU D X, CHEN H Y, et al.Study on the Force Chain Characteristics with Coal Dust Layer and the Three-Body Contact Stiffness[J]. Particuology, 2024, 92: 288-304.
[17] JIA T, ZHANG Y W, CHEN J K, et al.Dynamic Simulation of Granular Packing of Fine Cohesive Particles with Different Size Distributions[J]. Powder Technology, 2012, 218: 76-85.
[18] LI Y, CHENG X W, LI G J, et al.Effect of Particle Size on Dynamic Mechanical Behaviors of W Particles/Zr-Based Bulk Metallic Glass Composites[J]. Journal of Alloys and Compounds, 2021, 885: 160545.
[19] LESZCZYŃSKI J S. Sensitivity Analysis of the Dynamics of Fine and Ultrafine Particles Using DEM[J]. Nonlinear Dynamics, 2023, 111(3): 2591-2605.
[20] ZHAO L S, SUN H, LIU M C, et al.Numerical Study on Inverse Grading Segregation Mechanism of Single Coarse Particles with Different Particle Sizes under Two- Dimensional Cyclic Shear[J]. Physics of Fluids, 2025, 37(2): 023302.
[21] YOU Z S, LI Y H, LIU T, et al.Stress-Strain Response and Deformation Behavior of Hydrate-Bearing Sands under Different Grain Sizes: A Particle-Scale Study Using DEM[J]. Energy, 2024, 290: 130213.
[22] YAN P, FANG Q, ZHANG J H, et al.Experimental and Mesoscopic Investigation of Spherical Ceramic Particle Concrete under Static and Impact Loading[J]. International Journal of Impact Engineering, 2019, 128: 37-45.
[23] YAN W, KOMVOPOULOS K.Contact Analysis of Elastic-Plastic Fractal Surfaces[J]. Journal of Applied Physics, 1998, 84(7): 3617-3624.
[24] KANG G, NING Y J, LIU R, et al.Simulation of Force Chains and Particle Breakage of Granular Material by Numerical Manifold Method[J]. Powder Technology, 2021, 390: 464-472.
[25] QIAN H Y, XU C S, WU W, et al.A Hypoplastic Model Considering Grain Breakage and Wetting Effect for Granular Material[J]. Computers and Geotechnics, 2024, 171: 106329.
[26] PAPANIKOLAOU M, SALONITIS K.Fractal Roughness Effects on Nanoscale Grinding[J]. Applied Surface Science, 2019, 467: 309-319.
[27] MIAO X M, HUANG X D.A Complete Contact Model of a Fractal Rough Surface[J]. Wear, 2014, 309(1/2): 146-151.
[28] CHEN X Z, ELLIOTT J A.On the Scaling Law of JKR Contact Model for Coarse-Grained Cohesive Particles[J]. Chemical Engineering Science, 2020, 227: 115906.
[29] CHEN J, KRENGEL D, NISHIURA D, et al.A Force-Displacement Relation Based on the JKR Theory for DEM Simulations of Adhesive Particles[J]. Powder Technology, 2023, 427: 118742.
[30] 张惜图, 胡胜勇, 武玺, 等. 煤粉侵入对支撑裂缝渗透率的动态影响规律[J]. 煤炭学报, 2024, 49(5): 2338-2346.
ZHANG X T, HU S Y, WU X, et al.Dynamic Influence of Coal Fine Intrusion on Propped Fracture Permeability[J]. Journal of China Coal Society, 2024, 49(5): 2338-2346.
[31] KALIN M, POLAJNAR M.The Wetting of Steel, DLC Coatings, Ceramics and Polymers with Oils and Water: The Importance and Correlations of Surface Energy, Surface Tension, Contact Angle and Spreading[J]. Applied Surface Science, 2014, 293: 97-108.
[32] TAVARES L M, KING R P.Modeling of Particle Fracture by Repeated Impacts Using Continuum Damage Mechanics[J]. Powder Technology, 2002, 123(2/3): 138-146.
[33] TAVARES L M.Analysis of Particle Fracture by Repeated Stressing as Damage Accumulation[J]. Powder Technology, 2009, 190(3): 327-339.
[34] TAVARES L M, DAS NEVES P B. Microstructure of Quarry Rocks and Relationships to Particle Breakage and Crushing[J]. International Journal of Mineral Processing, 2008, 87(1/2): 28-41.
[35] TAVARES L M, DAS CHAGAS A S. A Stochastic Particle Replacement Strategy for Simulating Breakage in DEM[J]. Powder Technology, 2021, 377: 222-232.
[36] TAVARES L M.Chapter 1 Breakage of Single Particles: Quasi-Static[M]. Amsterdam: Elsevier, 2007: 3-68.
[37] TAVARES L M, DE CARVALHO R M. Modeling ORE Degradation during Handling Using Continuum Damage Mechanics[J]. International Journal of Mineral Processing, 2011, 101(1/2/3/4): 21-27.
[38] 张强, 吴泽光, 吴泽洋, 等. 采煤机导向滑靴力学在线测试与分析[J]. 工程设计学报, 2017, 24(6): 694-701.
ZHANG Q, WU Z G, WU Z Y, et al.Research on Online Testing and Analysis of Guide Foot Force of Shearer[J]. Chinese Journal of Engineering Design, 2017, 24(6): 694-701.
[39] FANG C F, GONG J, NIE Z H, et al.DEM Study on the Microscale and Macroscale Shear Behaviours of Granular Materials with Breakable and Irregularly Shaped Particles[J]. Computers and Geotechnics, 2021, 137: 104271.
[40] MA G, CHEN Y, YAO F H, et al.Evolution of Particle Size and Shape towards a Steady State: Insights from FDEM Simulations of Crushable Granular Materials[J]. Computers and Geotechnics, 2019, 112: 147-158.
[41] ZHAO G, XIONG Z L, JIN X, et al.Prediction of Contact Stiffness in Bolted Interface with Natural Frequency Experiment and FE Analysis[J]. Tribology International, 2018, 127: 157-164.
基金
国家自然科学基金项目（52204214,52474173,52174115）; 中国博士后科学基金面上项目（2023M741502）; “兴辽英才计划”项目（XLYC2403090,XLYC2402035）; 辽宁省自然基金联合基金计划项目（20240303）; 辽宁省教育厅基本科研项目（LJ212410147038）
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